Return flange forming machine



Sept. 16, 1958 H. D. KESLER ET AL RETURN FLANGE FORMING MACHINE 3 Sheets-Sheet 1 Filed Jan. 3, 1956 R, M J 0 M 5 m a R i V 5 Sept. 16, 1958 H. D. KESLER ET AL RETURN FLANGE FORMING MACHINE I 5 Sheets-Sheet 2 Filed Jan. 3, 1956 JNVENTOR5 firmwewm Sept. 16, 1958 Filed Jan 3, 1956 H. D. KESLER ET AL RETURN FLANGE FORMING MACHINE Q 3 Sheets-Sheet 3 BYW HTTO/PNEYS United States Patent 9 RETURN FLANGE FORIVHNG MACHINE Howard D. Kesler and Vernon I. Bormann, San Antonio, Tex.

Application January 3, 1956, Serial No. 557,218

4 Claims. (Cl. 153-25) (Granted under Title 35, U. S. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the United States Government for governmental purposes without payment to us of any royalty thereon.

This invention relates to return flange forming machines, and more particularly, to machines of this sort which may be employed for forming a return flange on the border of a sheet or sheet metal rib by power.

In forming a return flange on a sheet metal rib, heretofore, it has been customary to use a die and to bend the border of a sheet metal rib over the die by hand operated tools. Such an operation usually requires considerable skill and care on the part of the operator and considerable time in producing the final product. Furthermore, the work is fatiguing and, consequently, both the quantity and the quality suifer therefrom.

It is therefore the purpose of the present invention to provide a machine whereby the forming of return flanges on sheet metal work or aircraft ribs by manually operated tools is eliminated by the use of power forming dies.

A return flange forming machine, according to the present invention, is further characterized by its advantages, for example, of expediting the operation of progressive shaping or forming of the return flanges and of improving the accuracy and speed of the operation while relieving the operator of this arduous work, which operator may devote his entire time and attention to the properly placing of the work piece with respect to the bending dies and, generally, with the supervision of the proper functioning of the return flange forming machine. Also, any strains set up in the flange during the operation of bending the sheet metal work by manually operated tools, which strains usually cause buckling or distorition of the sheet metal work, are completely eliminated by the use of the return flange forming macine of the present invention.

According to the present invention, the return flange forming machine comprises a die pivotally mounted on a supporting frame and, locked in a stationary position, and a power driven cooperating die slidably supported by the supporting frame for reciprocation toward and from the locked die, the dies having cooperating bending surfaces, whereby a return flange may be formed on the border of sheet metal work positioned between the dies. This machine may be powered by operating the movable die by an electric motor. However, a pneumatic drill motor may also be employed for power with excellent results.

These and other features of the present invention are described in detail below in connection with the accom panying drawing, in which like reference characters refer to like parts in the several figures:

Figure 1 is a view in perspective of a return flange forming machine embodying the present invention;

Figure 2 is a vertical longitudinal section of the machine shown in Figure 1, parts thereof being shown in elevation;

Figure 3 is a plan view, partly in section taken along the line 33 in Figure 2; and

Figure 4 is an enlarged view in perspective of the movable die provided in the machine of the present invention shown in Figure 1.

Referring now in detail to the drawings, the embodiment of the return flange forming machine of the present invention illustrated in Figure 1 is indicated generally by the reference numberal 10, and, as shown, comprises a supporting frame 11 consisting of members 12, which members 12 are attached rigidly to a platform 14 or the like, as by bolts 15 extending through openings 16 in the platform 14 and screwed into the bottom-side of the members 12, or the members 12 may be attached by welding if so desired.

The frame 11 is adapted to support a vertically slidable supporting block 17 arranged between the frame mem-bers 12 and guided thereon for vertical movement by pins 18 secured in the sides of the block 17 and extending through guideways 19 on the frame members 12 for a reason which will be explained further below.

The block 17 is also provided with locking bolts 20 extending through slots 20 on the frame members 12, whereby the block 17 may be adjustable retained at any desired elevation by tightening the bolts 20 against the sides of the frame members 12. The block 17 is further provided with a bore 21 through which extends a piston rod 22 of a movable cooperating die 23 for reciprocation toward and from a cooperating die 24 while forming a return flange 25 one the border of a sheet metal rib, indicated at 26, which is positioned between the dies 23 and 24 as shown in Figures 2 and 3. Die 24 is a removable and interchangeable die, made in different size heights for use in forming different flange heights on sheet. metal parts.

At an intermediate part of the members 12 above. block 17 there is pivotally mounted by a pin 27 an arm 25%, which arm 28 carries the stationary die 24 attached thereto as by bolts 29, whereby the arm 28 with the stationary die 24 may be swung to a raised position, as shown in dotted line on Figure 1, for position ing the sheet metal rib 26 between the dies 23 and 24 for forming the return flange 25 thereon. 'After the sheet metal work or rib 26 is placed in position, the die 24 may then be lowered by swinging the arm 28 to the lower position, whereby the die 24 will about the sheet metal rib 26 and hold the same in place. In orderthat the arm 28 with the die 24 be locked in the lower position, looking means are provided, including a cam lock 31) pivotally supported on the frame members '12 by pins 31 ex-; tending through holes 32, the camlock bearing against the upper surface of the arm 28 substantially adjacent its pivot pin 27 when the arm 28 is in the lower position as shown in Figure 2. The cam lock 30 may easily be operated by a handle 33 fixed thereto.

In the embodiment of the invention herein illustrated, the die 24 is formed of a rectangular plate or die block 34 having a substantially vertically disposed bending surface 35, which bending surface 35 is adapted to support the sheet metal rib or work 26 by butting the same during the bending operation to prevent buckling thereof, and a substantially horizontally disposed bending surface 36 against which the flange 25 is formed by the bending action of the movable die 23.

The movable die 23 is likewise formed with a substantially vertically disposed member 37 and a substantially horizontal member 38 angularly disposed with respect to the vertically disposed member 37, the members 37 and 38 having corresponding bending surfaces 39 and 40, respectively, arranged to form obtuse angles (greater than at the ends of the die 23, which obtuse angles graduate or progressively decrease to a right angle at substantially near the center of the die 23 as clearly shown 23 and 24- approac h each other during-the bending opera tion, permitting a sharp bend or curve to be formed but without strains or wrinkles.

Reciprocatory movement of the. movable die 23 toward and'from the die 24 is elfected by means of a crank 41 rigidly secured to the end of a power shaft 42 adapted to journal in a bore 43 of. a support member 44, which member 44 may be rigidly attached to the platform 14 or the like by screws 45, or any other means such as welding. As mentioned above, the power shaft 42 may be operated by a high speed electric motor, diagrammatically shown at 42'; or may also be operated by a pneumatic drill motor in place of an electric motor.

The crank 41 is further connected to the reciprocating piston rod 22 by a pitman 4.6. The pitman 46 may, as shown, be formed. in two oppositely threaded sections joinedby a nut47, oneof the threaded sections being pivotally connected to the crank 41 as indicated at 48, and

the other to the piston rod. 22 by a pin 49 extending through apertures on a yoke 50 at the end of the piston rod 22. The pitman 46 is arranged to function as a tumbuckle whereby the relation of the bending dies 23 and 24 may be both adjusted by the vertical adjustment of the block 17 on the frame 11 and the adjustment of the length of. the pitman 46 for compensating for the sheet metal thickness.

Preferably the upright side of sheet metal work or rib 26 may further be supported as it is fed between the bending dies 23 and 24 by pressure rollers 51 provided one on each side of the supporting frame 11, as shown in Figures I and 3. The pressure rollers 51 are each rotatably supported by a pin and yoke arrangement, as indicated at 52, at the end of a rod 53 slidably extending through a bore 54 formed on a flanged upright 55, the upright 55 being attached to the platform 14 or the like by screws 56 as shown in Figures 1 and 3. The rod 53 may be restrained from rotating by a groove and key arrangement, indicated generally by the reference numeral 57; and is also retained in the bore 54 by a pin 58 at the end thereof which extends from the bore 54. Each rod5-3 is further provided with a coiled spring 59 adapted to-yieldably retain the pressure roller 51 in the extended position, whereby-the sheet metal rib 26 may be held in A proper position by the pressure of the rollers 51 exerted thereon for accurately forming the flange return 25-.

The present invention has been described in detail above. for the purpose of illustration only and is not intended tobe limited by this description'or otherwise exceptas defined in the appended claims.

We claim:

1. A return flange forming machine comprising a supporting frame, a die pivotally mounted on said frame, locks means on said frame for locking said pivotal die in a stationary position, an adjustable block slidably engaging said frame, guide means on said adjustable block and guideways on said frame engaged by said guide means, and adjusting means between said block and said frame for adjusting said block vertically on said frame, a movable cooperating dieslidably supported by said block, and power means for reciprocating said movable die to and from said. pivotal locked cooperating die for forming a flange on the border of sheet metal work placed between said dies.

2. A return flange forming machine as defined in claim 1 wherein said movable die has a piston rod slidably supported in said adjustable block, and an adjustable connection between said piston rod and said power means for adjusting said movable die relative to the position of said adjustable block on said supporting frame.

3. A r-eturn'flange forming machine as defined in claim 1 and further characterized in that pressure rollers are yieldably mounted adjacent the opposite ends of said dies, said pressure rollers disposed for abutment with the sheet of metal. work for supporting the same while being fed between said dies.

4. A return flange forming machine comprising a supporting frame, a cooperating die pivotally mounted on said frame, lock means on said frame for locking said pivotal die ina stationary position, a power driven co.- operatingdie slidably mounted on said frame for reciprocation toward and from said locked die, said cooperating dies having. an entrance end and an exit end, said power driven cooperating die having a substantially vertically disposed member having a flat bending surface, and an angularly disposed member having a bending surface forming an obtuse angle with said flat surface of said substantially vertically disposed member at the entrance end of said power driven die and with said obtuse angle graduating to substantially a right angle near the center of'said' power driven die, whereby a flange may be formed on the border of sheet metal Work fed between said dies.

References Cited in the file of this patent UNITED STATES PATENTS 926,093 Brown June 29, 1909' 1,234,384 Pope July 24, 1917 1,448,567 Muller et al Mar. 13, 1923 2,178,926 Brickman Nov. 7, 1939 2,233,937 Hexdall Mar. 4, 1941 2,414,178 Sprinkle Jan. 14, 1947 2,633,891 Sawyer Apr. 7, 1953 FOREIGN PATENTS 804,926 Germany Mar. 8, 1951 

